Here are the SYSEX commands that can be sent with a tool like MIDI OX.

The handshake query identifies the device and polls things like the firmware revision:

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0xF0, 0x7E, 0x00, 0x06, 0x01, 0xF7
The device mode set sysex can put the device into one of four modes based on the value of the 7th byte in the following message:

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0xF0, 0x47, 0x7F, 0x7B, 0x60, 0x00, 0x04, 0x41, 0x08, 0x02, 0x01, 0xF7
0x40 is the default startup mode, 0x41 is Ableton mode. The APC20 has a fourth mode called note mode corresponding to 0x43. I’m not sure what this mode is useful for yet, as mode 0x41 seems to be the most useful for programming since it relinquishes full control over the device.

for now im trying the bomes midi translator need help with Cap keystrokes not working
here is what i have so far.. also can i control live effect sliders with midi? or change layout to reflect the 8 rows of buttons instead of 10?